Index: trunk/src/org/openstreetmap/josm/data/imagery/ImageryInfo.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/imagery/ImageryInfo.java	(revision 15735)
+++ trunk/src/org/openstreetmap/josm/data/imagery/ImageryInfo.java	(revision 15736)
@@ -412,5 +412,5 @@
             }
             if (!i.serverProjections.isEmpty()) {
-                projections = i.serverProjections.stream().collect(Collectors.joining(","));
+                projections = String.join(",", i.serverProjections);
             }
             if (i.noTileHeaders != null && !i.noTileHeaders.isEmpty()) {
Index: trunk/src/org/openstreetmap/josm/data/imagery/TemplatedWMSTileSource.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/imagery/TemplatedWMSTileSource.java	(revision 15735)
+++ trunk/src/org/openstreetmap/josm/data/imagery/TemplatedWMSTileSource.java	(revision 15736)
@@ -7,4 +7,5 @@
 import java.text.DecimalFormatSymbols;
 import java.text.NumberFormat;
+import java.util.Arrays;
 import java.util.Locale;
 import java.util.Map;
@@ -170,11 +171,6 @@
         Matcher m = PATTERN_PARAM.matcher(url);
         while (m.find()) {
-            boolean isSupportedPattern = false;
-            for (Pattern pattern : ALL_PATTERNS) {
-                if (pattern.matcher(m.group()).matches()) {
-                    isSupportedPattern = true;
-                    break;
-                }
-            }
+            boolean isSupportedPattern = Arrays.stream(ALL_PATTERNS)
+                    .anyMatch(pattern -> pattern.matcher(m.group()).matches());
             if (!isSupportedPattern) {
                 throw new IllegalArgumentException(
Index: trunk/src/org/openstreetmap/josm/gui/dialogs/changeset/query/UrlBasedQueryPanel.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/changeset/query/UrlBasedQueryPanel.java	(revision 15735)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/changeset/query/UrlBasedQueryPanel.java	(revision 15736)
@@ -92,6 +92,7 @@
                 + "<p><strong>" + tr("Examples") + "</strong></p>"
                 + "<ul>"
-                + String.join("", getExamples().stream().map(
-                        s -> "<li><a href=\""+s+"\">"+s+"</a></li>").collect(Collectors.toList()))
+                + getExamples().stream()
+                        .map(s -> "<li><a href=\""+s+"\">"+s+"</a></li>")
+                        .collect(Collectors.joining(""))
                 + "</ul>"
                 + tr("Note that changeset queries are currently always submitted to ''{0}'', regardless of the "
Index: trunk/src/org/openstreetmap/josm/gui/layer/GpxLayer.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/layer/GpxLayer.java	(revision 15735)
+++ trunk/src/org/openstreetmap/josm/gui/layer/GpxLayer.java	(revision 15736)
@@ -305,6 +305,7 @@
         if (Logging.isDebugEnabled() && !data.getLayerPrefs().isEmpty()) {
             info.append("<br><br>")
-                .append(String.join("<br>", data.getLayerPrefs().entrySet().stream()
-                        .map(e -> e.getKey() + "=" + e.getValue()).collect(Collectors.toList())));
+                .append(data.getLayerPrefs().entrySet().stream()
+                        .map(e -> e.getKey() + "=" + e.getValue())
+                        .collect(Collectors.joining("<br>")));
         }
 
Index: trunk/src/org/openstreetmap/josm/gui/tagging/ac/AutoCompletionManager.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/tagging/ac/AutoCompletionManager.java	(revision 15735)
+++ trunk/src/org/openstreetmap/josm/gui/tagging/ac/AutoCompletionManager.java	(revision 15736)
@@ -16,5 +16,4 @@
 import java.util.Set;
 import java.util.function.Function;
-import java.util.stream.Collectors;
 
 import org.openstreetmap.josm.data.osm.DataSet;
@@ -347,5 +346,5 @@
 
     private static List<AutoCompletionItem> setToList(AutoCompletionSet set, Comparator<AutoCompletionItem> comparator) {
-        List<AutoCompletionItem> list = set.stream().collect(Collectors.toList());
+        List<AutoCompletionItem> list = new ArrayList<>(set);
         list.sort(comparator);
         return list;
Index: trunk/src/org/openstreetmap/josm/io/GpxWriter.java
===================================================================
--- trunk/src/org/openstreetmap/josm/io/GpxWriter.java	(revision 15735)
+++ trunk/src/org/openstreetmap/josm/io/GpxWriter.java	(revision 15736)
@@ -397,6 +397,8 @@
                 // but otherwise the file is invalid and can't even be parsed by SAX anymore
                 String k = (e.getPrefix().isEmpty() ? "" : e.getPrefix() + ":") + e.getKey();
-                String attr = String.join(" ", e.getAttributes().entrySet().stream()
-                        .map(a -> encode(a.getKey()) + "=\"" + encode(a.getValue().toString()) + "\"").sorted().collect(Collectors.toList()));
+                String attr = e.getAttributes().entrySet().stream()
+                        .map(a -> encode(a.getKey()) + "=\"" + encode(a.getValue().toString()) + "\"")
+                        .sorted()
+                        .collect(Collectors.joining(" "));
                 if (e.getValue() == null && e.getExtensions().isEmpty()) {
                     inline(k, attr);